Notes of an IT Architect. Eugeny Shtoltc

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СКАЧАТЬ provision service (infrastructure department) for its quick approval. The content is indicated in the target architecture (detailed architecture) of the solution. She participates in the early stages of creating a service and in the acceptance tests of the solution within the framework of architectural control. The conceptual architecture is the source of artifacts for implementing and developing a detailed solution architecture. We can distinguish the following stages of creating a conceptual architecture: planning, creation, development of an incremental draft (sketch), approval, revision. In order for the diagrams to be understood by both the developer and the owner of the product, a short description (Architecture Decision Records, ADR) is needed: the goal, the essence of the solution, rejected options, rationale, consequences, affected systems, a link to the diagram and the originator's contacts.

      The corporate data bus is usually used to connect individual systems. For connections within the system – point-to-point network connection and their control using integration gateways. Integration gateways can and can be used between systems, but often, these systems are not protocol compatible and require their transformation, which is provided by the corporate data bus, but not provided by the integration gateway. And the use of a corporate data bus to connect the components of one system is expensive, since the asynchronous protocol will be loaded by other systems due to the fact that the message queue that implements it will be filled with messages from other systems and subsequent messages will wait for their sending, which causes delays in data transmission… For the exchange of large amounts of data between systems and within systems – distributed information storage.

      With the layers we figured out, now, imagine the architecture as a layer cake. We can cut off a piece from it and narrow it down in more detail, but the number of layers in all pieces of this pie will be the same. By analogy, we can divide the corporate architecture into chunks. These pieces can be separate systems that are directly used on the business layer, or it can be a group of these applications developed by some department or department. The pie itself is the corporate architecture, and the piece is the solution (service) architecture. Enterprise architecture appears when we need to add new pieces to the pie, while the pieces are the architecture of the solution, and the rules according to which are made, for example, the number of layers – corporate architecture standards, cakes and cream – providing technologies for corporate architecture.

Enterprise Architecture

      Corporate architecture is the architecture of the entire IT landscape of a company. A corporate architect is guided by the principles of creating architecture, a kind of constitution. The principles are described in the third section of TOGAF 9.2 under clause 20. They govern which requirements, for example, the principle of customer focus or lean manufacturing will meet. It is important that all participants (stakeholders) agree to adhere to the same principles. The principles are categorized according to their applicability to the architecture layers: business, data, application, and technology.

      In practice, corporate architecture develops in three directions: unification of technologies, development of conceptual architectures, unification of the landscape. A landscape is understood not so much as an AS map, but as a set of unified solutions on the basis of which a business system is built, and with which it interacts, usually with infrastructure systems (logging, monitoring). To build the business system itself, unified solutions and technologies are used. To unify solutions, old solutions are adapted or new solutions are created, the customer of which is the department of corporate architects. To unify technologies, working groups of corporate architects are created – researchers who test the capabilities of existing solutions, analogs and make decisions either on the distribution of existing ones, or on the implementation of new ones. On the basis of research, architects – researchers create standards that describe the boundary possibilities of their applicability and regulate their use. According to GOST 1.1-2002. Standard: "a normative document that is developed on the basis of consensus, adopted by a recognized body at the appropriate level and establishes rules, general principles and characteristics for general and repeated use concerning various activities or their results, and which is aimed at achieving an optimal degree of harmonization in a certain area". It is important to emphasize that the standard fixes the agreements already found and that the stakeholders are interested in its implementation. If this is not the case, then the standard will not be met. Depending on the activities, the corporate architect may have different customers: the management of the organization, the regulatory departments (security, support, and others), the development teams of platform solutions, the architects of the development teams (to create a conceptual architecture of their future service). To maintain standards compliance, their requirements need to be validated through automated means, such as embedded in development tools and DevOps, or running validations at runtime. For this, it is necessary that the requirements of the standard are not only formalized, but also machine-readable. Not only the implementation, but also the architecture itself can be checked automatically. At the same time, checking the architecture should be carried out especially carefully, since its change over time is especially expensive afterwards. The principles of checking the corporate architecture and the solution architecture are different, since the corporate architecture is not just the sum of the designs of all solutions – it has different tasks.

      When building a business system, it will be opened from existing unified solutions, new functionality, and already existing technologies and infrastructure systems will be used. For example, unification and standardization of a set of programming languages. Here, the criteria are, among other things, the economic indicators of the development cost (the speed of development in a certain language and the cost of the developers themselves with the necessary qualifications in this language), guarantees for support (the availability of a sufficient number of free personnel and resume), the complexity of support, outsourcing and others.

      Enterprose Architect participates in the service development process at least in two stages – checking the developed conceptual architecture of the service and checking the compliance of the detailed architecture of the developed service with it and the standards for acceptance tests. In practice, he makes the conceptual architecture of the service himself and adds it to the service map himself, so he has the necessary experience and knowledge of all standards. In practice, Enterprose Architect assists the service architect in developing the detailed architecture of the service in its drafting and conceptual architecture in accordance with the vision of the service architect. In fact, the conceptual architecture is the architecture for integrating a service with other services to bring it into the service landscape, while the detailed architecture is the implementation of the service in accordance with the expectations of stakeholders (customers, controlling departments). It is the implementation that must comply with the restrictions imposed by Enterprise Architect on the implementation, for example, to unify technologies. If there is no collaboration, then Enterprise Architect becomes a regulatory body that blocks the deployment of the service with critical remarks or sets a technical debt with a deadline for elimination.

      An enterprise architect, when developing a conceptual architecture, negotiates with the service architects with whom his service needs to integrate and finds compromise solutions, as well as other stakeholders, such as security personnel. Having agreed, he brings to a higher level of agreement, to confirm the consensus. An enterprise architect needs knowledge of services and standards, communication skills and knowledge of integration architect, such as an enterprise service bus and the ability to quickly create an architecture with insufficient information in a tightly constrained time frame.

      A more lenient auditing-based standards review process can be applied, which can often be boiled down to checklists or automatic compliance checks. In practice, the service architect can go through such checklists under the guidance of Enterprise Architect for correct interpretation at the very beginning and then go through as necessary to correct compliance. Modern systems provide their setting in the form of configuration files, which allows automating the check against a list of such systems and their configuration files. Most of them work in asynchronous mode, that is, the states of the corresponding systems are asynchronously brought to the state described in these configuration files – IaaC. In most cases, the state to which the system is reduced can be obtained in a declarative form in either JSON or YML format. These СКАЧАТЬ